Dashpot brake for scales



June 9, 1931- c. F. M. VAN BERKEL ET Al. `Y1,809,084

DASHPOT BRAKE FOR SCALES Filed Jan. l2, 1928 mmfxeffg Patented June 9, 1931 vUNITED STATES PATENT Aori-"1er:

CORNELIS F. M'. VAN BERKEL, OF WASSENAAR, AN D' ADRIANUS VAN DUYN, OF ROTTER- DAM, DTETHERLANDS, ASSIGNORS TO NAAMLOOZE VENNOOTSCHAP MAATSCHAPPIJ TOT VERVAAR'DIGING VAN SNIJMACI-IINES VOLGENS VAN BERKELS PATENT EN VAN ANDERE WERKTUIGEN, OF ROTTERDAM, NETHERLANDS, A LIMITED LIABILITY COMPANY DASHPOT BRAKEFOR- SCALES y Application led January 12, 1928, Serial No. 246,334, and in Germany January 31, 1927.

The present invention relates to an improvement in dash-pots designed primarily for use as a brake for weighing scales.

Among the most important objects of the invention is the provision of a device of the class described which may be relied upon to develop uniform stresses on the parts of the scale which are directly or indirectly affected thereby. Heretofore, this desirable operation on the partof a scale brake has been entirely lacking with the result that scales so equipped have not developed the same efliciency as is possible by the use of our' improvements. Y

Another object of the invention is to construct the device in such a manner as to avoid the undesirable spraying and splashing of the cushioning liquid, usually oil, when the device is in operation.

Still another object of the invention is the provision of means to prevent the escape of the cushioning liquid should the scale be tilted as it is quite likely to be during shipment or being otherwise handled.

lVith these and other objects in view, the salient features of the invention will now be more particularly referred to with reference to the accompanying drawing in which the construction and co-operation of the parts thereof are illustrated. j

In said drawing the figure is a view in vertical section of a practical embodiment of the device andin which 5 represents a cylinder cast or otherwise formed to provide an extension 6 at the top thereof. The extension 6 is flared outwardly between the cylinder 5 and the perpendicular wall 7 which terminates in an open top having an external annular flange 8. This open top of the extension is normally closed by a lid or cover 9 which is made with an insetannular rim 10 to lit the inside diameter of Vthe opening with theedge of Vthe cover resting upon the flange 8. The center of the coveris provided with a countersunk area 11 which surrounds an opening 12. The opening 12 is made to accommodate a cylindrical sleeve 13 which projects Vinto the extension 6 of the cylinder and is supported therein by the ila-nge 14 which occupies vthe countersunk area 11. The sleeve 13 provides a guide for the slidably supported inner sleeve 15 which connects the sliding collar 16 with the regulating lever 17. This lever is pivoted, as at 187 to a post 19 on top of the cover 9 and the bifurcated or yoked end 20 of the lever straddles the tube 15 and is pivoted thereto as at 21. The opposite end` of the lever is provided with aninternallythreaded eye 22 for the reception of the threaded adjusting post23. One end Yof the post ismade with a button 24 which is confined with freedom of rotation in a suitable mounting 25 riveted or otherwise suitably secured upon the cover 9. By using a screw driver or other turning tool or key, the post 23 may be turned in the' eye 22 to rock the 'lever 17 and slide the collar 16 by means of its connection with the slidably mounted sleeve 15. The purpose of this assembly is to control the effect port area of the openings 26, the reasons for which will be presently described.

Arranged at the top of the cylinder 5 and partitioning the same from the extension. 6 is a horizontal partition 27 supporting a centrally and downwardly depending inner cylinder 28, the same terminating in an open top 29 in which the collar 16 is fitted to slide and an open bottom 30.

The piston 31 is mounted to reciprocate .within the area of the cylinder 5 and the same is made with a radial flange 32 fitting the Walls of the outer cylinder 5 without undue friction. The depending portion of the piston telescopeslwith the inner cylinder 28 and closes the end thereof. A piston rod 33 is secured t0 the piston, as at 34,' vand extends upwardly through the inner cylinder 28 and the tube 15 with its'projecting end equipped with a yoke 35 or the like asy a connection with the `weighing mechanism of the scale. A by-pass pipe 36 .communicates at one end 37 with the lower part of the cylinder `with its oppositeend projecting into the cylinder and connecting with one of the openings 26 in the inner cylinder 28. f o

The device operates substantially as follows: When the piston 31 moves downwardly in response to a thrust on the rod 33 from the Weighing mechanism of the scale, the liquid belovv the radial flange 32 in the bottom part of the cylinder is forced through the end 37 of the by-pass pipe 36 and out the end 38 whichV is connected to one ofthe openings 26 in the inner cylinder. At the same time liquidY Within the inner cylinder 28 is forced through the remaining openings 26 into the space above the radial flange 32.

This function cushions the down stroke of the piston.

When the piston moves upwardly in response to a pull on the piston rod from the Weighing mechanism, the flange 32 of the piston displaces the liquid above the same through the openings 26. At the same time liquid Within the inner cylinder is forced through the end 38 of the by-pass pipe and through it into the bottom of the cylinder.

The movement of the displaced liquid and hence also the movement ofthe piston may be accelerated or retarded by regulating the effective .port area of the openings 26 by adjusting the collar 16 over the same, as previously stated.

There is nothing to prevent the liquid from occupying the space in the extension 6 of the cylinder on the upstroke of the piston excepting that the piston creates a partial vacuum in the'by-passpipe 36 which 'encourages the liquid to enter the same as the direction of least resistance.

Obviously those skilled in the art may make various changes in the details and arrangement of parts Without departing from the spirit and scope oftheinvention as defined by the claims hereto appended, and We'wish therefore not to be restricted to the precise construction herein disclosed.

We claim 1. A brake for Weighing scales comprising an outer cylinder, an inner cylinder of smaller diameter centrally disposed Within the outer cylinder and havingan open end terminating above the bottom of the outer'cylinder, a stepped piston mounted for reciprocation in the outery cylinder While telescoping With the inner cylinder vand closingthe end thereof, a lradial vflange on the piston fitting the diameter ofthe outer cylinder,

and a piston rod for the pistonprojecting througha closed top for the outer cylinder.

2. A brake for Weighing scales comprising an outer cylinder, an inner cylinder `of' smaller diameter centrally disposed Within the outer cyinder and having'an open end'terminating above the bottom of the outer cylinder, a stepped piston mounted for reciprocation in the outer' cylindervvhile telescoping With the inner'cylinder `and closingthe end thereof, a radial flange on the `.piston fitting the diameter of the outer cylinder, and a `piston rod for the piston projecting v'through a closed top for the outer cylinder, said pis'- `ton rod extending through the inner oylin.-

der and through a sleeve supported in an opening in the closed top of the outer cylinder.

' 3. A dash-pot comprising a cylinder'witliin a cylinder, a piston mounted for reciprocation therein and telescoping with the innercylinder, said inner cylinder having a by-pass opening communicating with the outer cylinder, and means for regulating the effective port area of said opening comprising means mounted to slide across said opening, and means for adjusting the position thereof relative of said opening comprising a sleeve slidably mounted Within an opening in the top of the outer cylinder, a pivoted lever on the top cylinderconnected at one end to said sleeve with its opposite end provided with means for adjustably .rocking the same about its pivot to slide said sleeve.y

4C. A dash-pot having a by-pass opening,

and means for controlling the effective port area thereof comprising a slidablymounted collar mounted to move across said port, and means for adjusting the position of said collar relatively of said opening comprising a lever pivoted intermediate its ends,- means for connecting one end of said lever to said collar, and adjusting means at the opposite end of said lever comprising a post threaded through an eye on the end of the lever vand a mounting in which the Vend of said post is confined with freedom of rotation.

5. The combination as set forth in claim 3 and in which said by-pass opening is provided in a ,cylinder enclosed Within an outer .Lfff

cylinder, said outer lcylinder being closed to atmosphere and having a piston mounted for reciprocation therein and telescoping with the inner cylinder, and a by-pass pipe connecting the top of the inner cylinder jig-- with the bottom of the outer cylinder. i

6. A ,dash-pot comprising anouter cylinder having an enlarged extension at the top thereof, a partition in said cylinder dividing the bottom portion of the -cylinder from said enlarged extension, an inner cylinder supported by said partition centrally of said outer cylinder, said inner cylinder extending intothe bottom portion of the outer cylinder, a-.piston mounted for reciprocation -insaid outer cylinder and telescoping Vwith said inner 'cylinder-and a by-pass pipe connecting the top of the .inner cylinder with fthe bottom of theouter cylinder.

7. A dash-pot comprising an outer cylinder having an enlarged extension at lthe top thereof, a `partition in saidzcylinder dividing the bottom portion of the cylinder .from said enlarged extension, an inner cylinder supported by said ypartition centrallyV of 'fifi' saidrouter cylinder, said inner cylinder `eX- tending into the bottom portion of the outer cylinder, a piston mounted for reciprocationin said outer ycylinder :andtelescoping withgsaid Vinner cylinder, a by-pass pipe'connecting the top of the inner cylinder with the bottom of the outer cylinder, and means for regulating the effective port area of the opening into said by-pass pipe.

8. A brake for weighing scales adapted to be operatively connected to the scale pan thereof to dampen its movement, comprising a cylinder within a chamber adapted to contain a fluid, a piston rod extending through said cylinder and having a piston shaped so as to slide on the exterior portion thereof, and a by-pass forming a means of communication between the space in said cylinder with the space within said chamber on the side away from the connection between said by-pass and cylinder.

9. A brake for weighing scales comprising a hollow chamber for containing a fluid, a cylinder within said chamber having one end in communication with the space in said chamber, a piston rod extending through said cylinder and having a piston thereof slidably mounted on the exterior portion of said cylinder, a by-pass forming a means of communication between the space in said cylinder with the space in said chamber on the side away from the connection between said by-pass and cylinder, and means for varying the effective cross-sectional area of the by-pass.

10. A brake for weighing scales comprising a hollow chamber for containing a fluid, a cylinder within said chamber having one end in communication with the space in said chamber, a piston rod extending through said cylinder and having a piston thereof slidably mounted on the exterior portion of said cylinder, a by-pass forming a means of communication between the space in said cylinder with the space in said chamber on the side away from the connection between said by-pass and cylinder, and asleeve slidably adjustable relative to the opening in the by-pass to vary the effective raae of flow of the fluid through said by-pass.

11. A device as claimed in claim 10 in which the sleeve has a pivotal connection with a pivoted lever, and means for adjusting the position of the pivoted lever to vary the position of the sleeve.

12. A dash-pot brake for scales comprising a chamber having a hollow cylinder therein and spaced from the side walls thereof, a piston slidably mounted on the exterior portion of said cylinder, a by-pass forming a connection between the interior of the cylinder and that portion of the chamber located below the piston, an opening in said cylinder for permitting fluid to pass freely between that portion of the chamber above the piston and the interior of the cylinder, and a sleeve for varying the effective size of the opening and the effective cross-sectional area of the by-pass.

13. A dash-pot brake for scales comprising a chamber having a hollow cylinder therein and spaced from the sidewallsthereof, a piston slidably mounted on the exterior portion of said cylinder, a by-pass forming a connection between the interior of the cylinder and that portion of the chamber located below the piston, an opening in said cylinder for permitting fluid to pass Jfreely between that portion of the chamber above the piston and the interio-r of the' cylinder, and a sleeve for simultaneously varying the effective size of the opening and the effective cross-sectional area of the by-pass.

14. A brake for weighing scales comprising an outer cylinder, an inner cylinder of smaller diameter centrally disposed within the outer cylinder and having an open end terminating above the bottom of the outer cylinder, a stepped piston mounted for reciprocation in the outer cylinder while telescoping within the inner cylinder and closing the end thereof, a radial flange on the piston fitting the diameter of the outer cylinder, a piston rod for the piston extending through the inner cylinder and through a sleeve supported in an opening in the top of the outer cylinder, a sleeve slidable within the innner cylinder, and an opening in the inner cylinder adapted to have its effective size varied by means of the sleeve within the inner cylinder.

15. A dash-pot having a by-pass opening and means for controlling the effective crosssectional area thereof, comprising a slidable collar mounted to move across one end of said by-pass, and means for adjusting the position of'said collar relatively to said end of said by-pass comprising a lever having a pivotal connection with said collar, and means for adjusting the position of the lever to position the collar in proper relation relav tive to the end of the by-pass.

16.. A dash-pot comprising a cylinder within a cylinder, a piston mounted for reclprocation in the outer cylinder and telescopmg with the inner cylinder, said piston extending substantially across the space between the cylinders, each of said cylinders being adapted to contain a fluid, and means for by-passing a fluid from said first cylinder to said second cylinder.

Intestimony whereof, we have signed our names to this specification.

Signed by C. F. M. VAN BERKEL, this 21st day of December, 1927.

CORNELIS F. M. VAN BERKEL. Signed by ADRIANUs VAN DUYN, this 21st day of December, 1927.

ADRIANUS VAN DUYN. 

